Observing log of individual spectra

Lithium abundances A(Li) range from 95-times solar (A(Li)~+3.0) on the warm end of the sample to 1/25 solar (A(Li)~-0.4) on the cool end. We confirm the tight relation of A(Li) with Teff and extend it to K-M stars with even smaller Li abundances than previously measurable. A formal relation with rotational period and velocity in the sense higher Li abundance for faster rotators is present.

Targets rotating faster than vsini of 6km/s (Prot~8d) appear Li saturated at A(Li)~3.0dex. CaII IRT fluxes for our sample indicate (logarithmic) chromospheric radiative losses R_IRT_ in the range -4.0 to -4.9 in units of the bolometric flux. These radiative losses also show a relation with Teff, Prot, and vsini, but opposite to A(Li) in an inverse sense with higher radiative losses for the slower=cooler rotators.

Longitudinal magnetic-field strengths were measured in the range zero to -100G and +150G with phase-averaged, disk-integrated, unsigned values <|B|> of 15.4+/-3.6(rms) G for targets warmer than ~5000K and 91+/-61(rms)G for targets cooler than this. These unsigned field strengths relate to Prot , vsini, and Ro_n_, but in a dual-slope fashion. The short-period bonafide single M-target RSP 348 was found to be a double-lined spectroscopic binary of dM3e+dM5e classification.

We conclude that the Rossby-number dependencies of the surface activity tracers A(Li), R'_IRT_ , and <|B|> on our Hyades dwarf sequence primarily originate from convective motions, expressed by its turnover time, and only to a smaller and sometimes inverse extent from surface rotation and its related extra mixing.